Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 18 de 18
Filtrar
Mais filtros











Intervalo de ano de publicação
1.
Rev. bras. saúde prod. anim ; 24: e20230020, 2023. tab, graf
Artigo em Inglês | VETINDEX | ID: biblio-1512757

RESUMO

This study aimed to analyze the seasonal variation of gastrointestinal parasitic infections in goats and sheep in São Luís, Maranhão, Brazil. Fecal samples were collected directly from the rectal ampulla of the animals to count the eggs per gram in the feces at 30-day intervals over the 12-month study period. This study included 40 small ruminants, comprising 22 goats (14 sows, 6 kids, and 2 sires) and 18 sheep (13 sows, 4 lambs, and 1 sire). The study assessed the variation in the excretion of gastrointestinal nematode eggs during the dry and rainy seasons. Coproculture was performed to identify third-stage larvae. In the 12 months of research and monthly sample collections, 95.9% and 82.3% of the eggs detected were endoparasites in the fecal samples of the goats and sheep, respectively. Eimeria spp. oocysts were present in 50.6% and 30.4% of the goat and sheep fecal samples, respectively. The results indicated that the mean number of eggs per gram of feces was higher in the rainy season than in the dry season in both goats and sheep. The genera of gastrointestinal nematodes identified via monthly coproculture tests were Haemonchus sp., Trichostrongylus sp., and Oesophagostomum sp. Thus, gastrointestinal nematode parasitism was higher in goats and sheep during the rainy season than in the dry season, and the genera Haemonchus sp. and Trichostrongylus sp. were the most prevalent.(AU)


O objetivo deste estudo foi verificar as infecções por parasitas gastrintestinais em caprinos e ovinos de acordo com a variação sazonal no município de São Luís, estado do Maranhão, Brasil. Foram realizadas colheitas de amostras de fezes diretamente das ampolas retais dos animais a cada 30 dias do experimento para contagem de ovos por gramas de fezes no período de 12 meses. Um total de 40 pequenos ruminantes foram utilizados no presente estudo. Destes, 22 eram caprinos (14 matrizes, 6 cabritos e 2 reprodutores) e 18 ovinos (13 matrizes, 4 cordeiros e 1 reprodutor). Foi mensurada a variação na excreção de ovos de nematoides gastrintestinais durante o período seco e chuvoso. Foi realizada cultura e identificação das larvas de terceiro estágio. Considerando os 12 meses de pesquisa e a quantidade de coletas mensais, o número de ovos detectados nas amostras fecais de caprinos e de ovinos foram de 95,9 e 82,3% de endoparasitos, respectivamente. Quanto à presença de oocistos de Eimeria spp, foi identificada frequência de 50,6% em caprinos e 30,4% em ovinos. Os resultados indicaram que, no período chuvoso a média dos ovos por grama de fezes foi maior, para as duas espécies estudadas. Os gêneros de nematoides gastrintestinais identificados recuperados da coprocultura, realizado mensalmente, revelou presença de Haemonchus sp. seguido por Trichostrongylus sp. e Oesophagostomum sp. Conclui-se que no período chuvoso o parasitismo por nematóides gastrintestinais em caprinos e ovinos foi maior e os gêneros Haemonchus sp. e Trichostrongylus sp. foram os mais prevalentes.(AU)


Assuntos
Animais , Doenças Parasitárias em Animais/diagnóstico , Ruminantes/parasitologia , Ovinos/parasitologia , Helmintíase Animal/diagnóstico , Estações do Ano , Brasil
2.
Acta Trop ; 232: 106488, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35533712

RESUMO

Triatoma guasayana (Hemiptera, Reduviidae), considered a secondary vector of Chagas disease, invades rural dwellings through flight dispersal during the warm season in semi-arid Chaco of Argentina. The objective of this study was to define and compare morphometrics features in the relative body size and wing shape of T. guasayana related to temperature and rainfall between spring, summer and end of summer. A total of 188 adults were collected in rural communities in the northwest of the province of Córdoba (central Argentina). Relative body size [body length (mm) / wing length (mm)] and 11 landmarks on the right wing were recorded. The temperature ( °C) and precipitation (mm) data were extracted from the MODIS sensor and Terra Climate dataset, respectively. Correlations between climatic variables and morphological variation were analyzed using Partial Least Square (PLS). Males at the end of summer were smaller than those at spring or summer (F = 4.48; df = 2; p = 0.01), whereas females were similar in relative body size at all seasons (F = 0.76; df = 2; p = 0.47). The PLS in males showed a correlation between wing shape and temperature (r = 0.48; p = 0.03) and precipitation (r = 0.50; p = 0.02) while in females only the temperature was the correlation significant (r = 0.35; p = 0.03). Triatoma guasayana has elongated and thin wings in spring that become short and wide at the end of summer. The morphotype of early summer could allow sustained long-duration flights, while the morphotype of end of summer would be related to short flights, correlated with the dispersive behavior of the species. The results in this study suggest that wing morphology of T. guasayana has phenotypic plasticity, and that temperature and rainfall could be considered modulator factors during the developmental stage.


Assuntos
Doença de Chagas , Triatoma , Animais , Argentina , Feminino , Humanos , Masculino , População Rural , Estações do Ano , Temperatura , Triatoma/anatomia & histologia
3.
Braz. arch. biol. technol ; Braz. arch. biol. technol;65: e22210347, 2022. tab, graf
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1364434

RESUMO

Abstract: Olive is grown in semi-arid climatic conditions; however, little is known about mineral changes in olive plant and nutrient requirements during the production period. Hence, the current study was conducted under Pothwar agro-climatic conditions in order to select appropriate stage of macronutrients (N, P, K) application in relation to soil and leaf nutritional status during 2017 and 2018 growing seasons. Soil and leaf analysis were performed at four different phenological stages (i.e. flowering, fruit setting, fruit enlargement and fruit maturity stages). The results revealed that the assessed macronutrient in leaf and soil varied significantly among varieties, phenological stages and growing year. The results revealed also that nitrogen level was found to decrease from fruit set (1.56%) to fruit enlargement stage (1.47%). Leaf and soil N, P and K contents were found higher before the flowering (stage 1) and depleted after fruit harvesting (stage 4), regardless of olive varieties. However, high yielding varieties showed lower nutrients after fruit harvesting (stage 4). Therefore, N content in leaf and soil gradually decreased during fruit growth and development. Whereas, K content in leaf and soil sharply declined from fruit maturity to fruit ripening stage. Overall, the trend of nutrient depletion showed that plants need phosphorus for fruit setting, nitrogen before and after fruit setting, and potash after pit hardening or at oil accumulation stages.

4.
Sci Total Environ ; 759: 144312, 2021 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-33333330

RESUMO

At the beginning of the SARS-COV-2 outbreak in Brazil, there was a striking difference between the contamination rate in the Amazonian States and the South and the Southeast States. The regions near the Amazon rainforest presented much higher and faster contaminations. This paper attempts to explain this phenomenon through a global analysis of the COVID-19 epidemic in Brazil. It also investigates the relationship between climate conditions and airborne transmission with the evolution of contagion in the Amazonian states. The method of investigation of the spread of SARS-COV-2 in these different macro-environments was based on the analysis of three extensive daily official databases on the number of deaths, the percentage of adherence of the populations to the restriction policies, and the local climatic conditions. Besides, the social conditions in those States were also taken into account. Then, it was compared the epidemiologic results for States with very different climatic characteristics and that had adopted, almost simultaneously, similar social isolation measures. However, all these analyses were not able to explain the remarkable difference in the evolution of the pandemic among Brazilian regions. So, it was necessary to invoke airborne transmission, facilitated by the very high air humidity, as a decisive factor to explain the faster evolution of contagion in the rainforest region. Air humidity seems to be the most important climatic factor in viral spreading, while usual ambient temperatures do not have a strong influence. Another very important result of this analysis was the observation that the onset of collective immunity may have been achieved with a contamination rate of about 15% of the Amazonian population.


Assuntos
COVID-19 , Surtos de Doenças , SARS-CoV-2 , Brasil/epidemiologia , COVID-19/epidemiologia , Humanos , Umidade , Floresta Úmida , Temperatura
5.
Ci. Rural ; 51(08): 1-12, 2021. tab, graf
Artigo em Inglês | VETINDEX | ID: vti-765648

RESUMO

The current article looks at the effects of climate change on agriculture, especially crop production, and influence factors of agricultural development in terms of their rational use in Pakistan. Due to the dependence of economic development, and agriculture in the South Asian region on access to renewable national resources and the associated vulnerability to climate change, the limited financial and professional resources of the Islamic Republic of Pakistan require a clear definition of national priorities in this area. In the preparation of this article, general scientific cognition methods, in particular, empirical-theoretical methods were used. Grouping and classification methods have been used to process and systematize the data. The ability to change productivity, depending on the variation of the average annual air temperature and the average annual precipitation rate, was considered using a two-factor regression model. The main finding of the study is that temperature and precipitation have a negative impact on agricultural production. This study can provide a scientific justification for the specialization of agricultural production in the regions of Pakistan as well as the execution of the necessary agricultural activities.(AU)


O objetivo deste artigo é examinar os efeitos das mudanças climáticas na agricultura, especialmente a produção agrícola e os fatores de influência do desenvolvimento agrícola em termos de uso racional no Paquistão. Devido à dependência do desenvolvimento econômico e da agricultura na região do sul da Ásia do acesso a recursos nacionais renováveis e à vulnerabilidade associada às mudanças climáticas, os recursos financeiros e profissionais limitados da República Islâmica do Paquistão exigem uma definição clara das prioridades nacionais nessa área. Na preparação deste artigo, foram utilizados métodos gerais de cognição científica, em particular métodos teórico empíricos. Os métodos de agrupamento e classificação foram utilizados para processar e sistematizar os dados. A capacidade de alterar a produtividade, dependendo da variação da temperatura média anual do ar e da taxa média anual de precipitação, foi considerada usando um modelo de regressão de dois fatores. A principal descoberta do estudo é que a temperatura e a precipitação têm um impacto negativo na produção agrícola. Este estudo pode fornecer uma justificativa científica para a especialização da produção agrícola nas regiões do Paquistão, bem como a execução das atividades agrícolas necessárias.(AU)


Assuntos
Mudança Climática/economia , Mudança Climática/estatística & dados numéricos , Agricultura/economia
6.
Ci. Rural ; 51(8)2021.
Artigo em Inglês | VETINDEX | ID: vti-762213

RESUMO

ABSTRACT: The current article looks at the effects of climate change on agriculture, especially crop production, and influence factors of agricultural development in terms of their rational use in Pakistan. Due to the dependence of economic development, and agriculture in the South Asian region on access to renewable national resources and the associated vulnerability to climate change, the limited financial and professional resources of the Islamic Republic of Pakistan require a clear definition of national priorities in this area. In the preparation of this article, general scientific cognition methods, in particular, empirical-theoretical methods were used. Grouping and classification methods have been used to process and systematize the data. The ability to change productivity, depending on the variation of the average annual air temperature and the average annual precipitation rate, was considered using a two-factor regression model. The main finding of the study is that temperature and precipitation have a negative impact on agricultural production. This study can provide a scientific justification for the specialization of agricultural production in the regions of Pakistan as well as the execution of the necessary agricultural activities.


RESUMO: O objetivo deste artigo é examinar os efeitos das mudanças climáticas na agricultura, especialmente a produção agrícola e os fatores de influência do desenvolvimento agrícola em termos de uso racional no Paquistão. Devido à dependência do desenvolvimento econômico e da agricultura na região do sul da Ásia do acesso a recursos nacionais renováveis e à vulnerabilidade associada às mudanças climáticas, os recursos financeiros e profissionais limitados da República Islâmica do Paquistão exigem uma definição clara das prioridades nacionais nessa área. Na preparação deste artigo, foram utilizados métodos gerais de cognição científica, em particular métodos teórico-empíricos. Os métodos de agrupamento e classificação foram utilizados para processar e sistematizar os dados. A capacidade de alterar a produtividade, dependendo da variação da temperatura média anual do ar e da taxa média anual de precipitação, foi considerada usando um modelo de regressão de dois fatores. A principal descoberta do estudo é que a temperatura e a precipitação têm um impacto negativo na produção agrícola. Este estudo pode fornecer uma justificativa científica para a especialização da produção agrícola nas regiões do Paquistão, bem como a execução das atividades agrícolas necessárias.

7.
Ciênc. rural (Online) ; 51(8): e20200110, 2021. tab, graf
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1249549

RESUMO

ABSTRACT: The current article looks at the effects of climate change on agriculture, especially crop production, and influence factors of agricultural development in terms of their rational use in Pakistan. Due to the dependence of economic development, and agriculture in the South Asian region on access to renewable national resources and the associated vulnerability to climate change, the limited financial and professional resources of the Islamic Republic of Pakistan require a clear definition of national priorities in this area. In the preparation of this article, general scientific cognition methods, in particular, empirical-theoretical methods were used. Grouping and classification methods have been used to process and systematize the data. The ability to change productivity, depending on the variation of the average annual air temperature and the average annual precipitation rate, was considered using a two-factor regression model. The main finding of the study is that temperature and precipitation have a negative impact on agricultural production. This study can provide a scientific justification for the specialization of agricultural production in the regions of Pakistan as well as the execution of the necessary agricultural activities.


RESUMO: O objetivo deste artigo é examinar os efeitos das mudanças climáticas na agricultura, especialmente a produção agrícola e os fatores de influência do desenvolvimento agrícola em termos de uso racional no Paquistão. Devido à dependência do desenvolvimento econômico e da agricultura na região do sul da Ásia do acesso a recursos nacionais renováveis ​​e à vulnerabilidade associada às mudanças climáticas, os recursos financeiros e profissionais limitados da República Islâmica do Paquistão exigem uma definição clara das prioridades nacionais nessa área. Na preparação deste artigo, foram utilizados métodos gerais de cognição científica, em particular métodos teórico-empíricos. Os métodos de agrupamento e classificação foram utilizados para processar e sistematizar os dados. A capacidade de alterar a produtividade, dependendo da variação da temperatura média anual do ar e da taxa média anual de precipitação, foi considerada usando um modelo de regressão de dois fatores. A principal descoberta do estudo é que a temperatura e a precipitação têm um impacto negativo na produção agrícola. Este estudo pode fornecer uma justificativa científica para a especialização da produção agrícola nas regiões do Paquistão, bem como a execução das atividades agrícolas necessárias.

8.
Ciênc. rural (Online) ; 51(08): 1-12, 2021. tab, graf
Artigo em Inglês | VETINDEX | ID: biblio-1480177

RESUMO

The current article looks at the effects of climate change on agriculture, especially crop production, and influence factors of agricultural development in terms of their rational use in Pakistan. Due to the dependence of economic development, and agriculture in the South Asian region on access to renewable national resources and the associated vulnerability to climate change, the limited financial and professional resources of the Islamic Republic of Pakistan require a clear definition of national priorities in this area. In the preparation of this article, general scientific cognition methods, in particular, empirical-theoretical methods were used. Grouping and classification methods have been used to process and systematize the data. The ability to change productivity, depending on the variation of the average annual air temperature and the average annual precipitation rate, was considered using a two-factor regression model. The main finding of the study is that temperature and precipitation have a negative impact on agricultural production. This study can provide a scientific justification for the specialization of agricultural production in the regions of Pakistan as well as the execution of the necessary agricultural activities.


O objetivo deste artigo é examinar os efeitos das mudanças climáticas na agricultura, especialmente a produção agrícola e os fatores de influência do desenvolvimento agrícola em termos de uso racional no Paquistão. Devido à dependência do desenvolvimento econômico e da agricultura na região do sul da Ásia do acesso a recursos nacionais renováveis e à vulnerabilidade associada às mudanças climáticas, os recursos financeiros e profissionais limitados da República Islâmica do Paquistão exigem uma definição clara das prioridades nacionais nessa área. Na preparação deste artigo, foram utilizados métodos gerais de cognição científica, em particular métodos teórico empíricos. Os métodos de agrupamento e classificação foram utilizados para processar e sistematizar os dados. A capacidade de alterar a produtividade, dependendo da variação da temperatura média anual do ar e da taxa média anual de precipitação, foi considerada usando um modelo de regressão de dois fatores. A principal descoberta do estudo é que a temperatura e a precipitação têm um impacto negativo na produção agrícola. Este estudo pode fornecer uma justificativa científica para a especialização da produção agrícola nas regiões do Paquistão, bem como a execução das atividades agrícolas necessárias.


Assuntos
Agricultura/economia , Mudança Climática/economia , Mudança Climática/estatística & dados numéricos
9.
Biosci. j. (Online) ; 36(6): 2050-2059, 01-11-2020. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1148058

RESUMO

The physiological quality of seeds is influenced by the climatic factors of production fields. The identification of the best conditions of P. maximum cv. Mombasa production fields allows the improvement of the seed sector. The aim of this work was to identify which climatic conditions of production fields can affect the physiological quality of P. maximum cv. Mombasa seeds. Nineteen plots from states of São Paulo (six from municipalities of Auriflama and three from Guzolândia) and Goiás (eight from Quirinópolis and two from Serranópolis), were collected by soil sweeping. The following parameters were evaluated: water content, germination rate, first germination count and germination rate index, seedling emergence in sand and field. Completely randomized design was used for all variables, with the exception of seedling emergence in field, since this variable required block design. Means were compared by the Scott-Knott test, at 5% probability. For the identification of the influence of climatic conditions on the physiological quality of seeds, multivariate statistical analysis was applied through Group and Principal Component Analysis. Production fields of Panicum maximum cv. Mombasa seeds presenting maximum temperatures above 32 ºC at flowering and natural fall stages produce seeds of low physiological quality. Production fields in which precipitation and high temperatures occur during natural fall and harvest of P. maximum cv. Mombasa seeds are not favorable to the production of seeds with high physiological quality.


A qualidade fisiológica das sementes é influenciada pelos fatores climáticas doscampos de produção. A identificação das condições dos melhores campos de produção de P. maximum cv. Mombaça permite aprimoramento do setor de sementes. O objetivo desse trabalho foi identificar quais condições climáticas dos campos de produção podem afetar a qualidade fisiológica das sementes de P. maximum cv. Mombaça. Foram avaliados dezenove lotes procedentes do estado de São Paulo (seis de Auriflama e três de Guzolândia) e Goiás (oito de Quirinópolis e dois de Serranópolis), colhidos por varredura do solo. Foram avaliados por meio dos seguintes parâmetros: teor de água, germinação, primeira contagem de germinação e índice de velocidade de germinação, emergência de plântulas em areia e em campo. Adotou-se delineamento inteiramente casualizado para todas as variáveis, com exceção da emergência de plântulas em campo, pois neste adotou-se delineamento em blocos. As médias foram comparadas pelo teste Scott-Knott, a 5% de probabilidade. Para a identificação da influência das condições climáticas na qualidade fisiológica das sementes aplicou-se análise estatística multivariada por meio de Análise de Agrupamento e Componentes Principais. Campos de produção de sementes de Panicum maximum cv. Mombaça que apresentam temperaturas máximas superiores a 32 ºC nas épocasde florescimento e degrana produzem sementes de baixa qualidade fisiológica. Campos de produção em que ocorram precipitações e altas temperaturas durante a degrana e à colheita de sementes de P.maximum cv. Mombaça não são favoráveis a produção de sementes com alta qualidade fisiológica.


Assuntos
Sementes , Análise Multivariada , Brachiaria , Panicum
10.
Oecologia ; 192(3): 745-753, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32016526

RESUMO

Biotic and abiotic factors may individually or interactively disrupt plant-pollinator interactions, influencing plant fitness. Although variations in temperature and precipitation are expected to modify the overall impact of predators on plant-pollinator interactions, few empirical studies have assessed if these weather conditions influence anti-predator behaviors and how this context-dependent response may cascade down to plant fitness. To answer this question, we manipulated predation risk (using artificial spiders) in different years to investigate how natural variation in temperature and precipitation may affect diversity (richness and composition) and behavioral (visitation) responses of flower-visiting insects to predation risk, and how these effects influence plant fitness. Our findings indicate that predation risk and an increase in precipitation independently reduced plant fitness (i.e., seed set) by decreasing flower visitation. Predation risk reduced pollinator visitation and richness, and altered species composition of pollinators. Additionally, an increase in precipitation was associated with lower flower visitation and pollinator richness but did not alter pollinator species composition. However, maximum daily temperature did not affect any component of the pollinator assemblage or plant fitness. Our results indicate that biotic and abiotic drivers have different impacts on pollinator behavior and diversity with consequences for plant fitness components. Even small variation in precipitation conditions promotes complex and substantial cascading effects on plants by affecting both pollinator communities and the outcome of plant-pollinator interactions. Tropical communities are expected to be highly susceptible to climatic changes, and these changes may have drastic consequences for biotic interactions in the tropics.


Assuntos
Polinização , Comportamento Predatório , Animais , Flores , Insetos , Plantas
11.
Rev. biol. trop ; Rev. biol. trop;67(2)abr. 2019.
Artigo em Espanhol | LILACS-Express | LILACS | ID: biblio-1507489

RESUMO

Los estudios fenológicos generan información que contribuye con el conocimiento de las relaciones entre especies y componentes abióticos de los ecosistemas, disponibilidad de alimento para animales y regeneración de cobertura boscosa. Crescentia alata es una especie arbórea abundante en el bosque tropical seco (BTs); su importancia ecológica, cultural y económica ha sido ampliamente reconocida y por eso existe interés en reproducir esta especie, pero antes es necesario conocer detalladamente su desarrollo fenológico. El objetivo de este estudio fue describir la fenología de C. alata en el BTs de Costa Rica. Se seleccionaron 20 árboles reproductivos en el Parque Nacional Santa Rosa para observar las siguientes fenofases: follaje, floración y fructificación por 14 meses entre 2015 y 2016. Esta especie produjo más follaje en junio, máxima floración en junio y octubre y mayor número de frutos maduros en enero. Los patrones fenológicos en C. alata se relacionaron con factores climáticos comunes, sobre todo precipitación, temperatura y humedad relativa. Los resultados más relevantes de este estudio podrían contribuir a la propagación, el manejo adecuado y la conservación de esta especie.


Phenological studies generate information that contributes knowledge on relationships of species and abiotic components of ecosystems, availability of food for animals and regeneration of forest cover. Crescentia alata is an abundant tree species in tropical dry forests; its ecological, cultural and economic importance has been widely recognized and for this reason there is an interest in reproducing this species, but previously it is necessary to understand its detailed phenological development. The aim of this work was to describe C. alata phenology in dry Costa Rican forests. Twenty reproductive trees were selected at the Santa Rosa National Park to observe phenophases (leaf flushing, flower production, and fructification) during 14 months from 2015 to 2016. Most foliage was observed in June, maximal floration in June and October, and the highest ripe-fruit number in January. Phenological patterns in C. alata were related to common climatic factors as rainfall, temperature, and relative humidity; other factors considered were wind speed, and sun radiation. The most significant phenological data registered for C. alata in this work may contribute to a better management and conservation of this species.

12.
Rev. biol. trop ; Rev. biol. trop;65(3): 1129-1141, Jul.-Sep. 2017. tab, ilus
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-897608

RESUMO

Abstract: Phytoplankton functional groups structure and species abundance vary according to environmental conditions. The present study investigated the natural and anthropogenic stressors that affect phytoplankton functional group biomass in a Brazilian semiarid region reservoir (Argemiro de Figueiredo reservoir). Sampling occurred between August 2007 and July 2009 on a bi-monthly basis for the first year, and in a monthly basis for the last two years. There were three collection points (PC: river confluence; PNC: near the cages; PD: dam site). The water environment analysis of abiotic variables included: temperature, transparency, coefficient of vertical light attenuation, dissolved oxygen, pH, electrical conductivity, alkalinity, dissolved inorganic nitrogen, and reactive soluble phosphorus. Phytoplankton samples were collected into a Van Dorn bottle, and were then preserved in acetic lugol and were quantified using an inverted microscope to determine phytoplankton density and biomass; the identified species were assembled in functional groups. The data were explored by canonical correspondence analysis. Individual analyses were made to test the temporal and spatial variability of the data and the factors that interfered most with the biotic and abiotic variables. Functional groups S1, SN, and K, consisting of filamentous Planktothrix agardhii (Gomont) Anagnostidis & Komárek, Cylindrospermopsis raciborskii (Woloszynska) Seenaya & Subba Raju, and the coccoid Aphanocapsa incerta (Lemmermann) Cronberg & Komárek, respectively, dominated the dry months when the water was warm, turbid, and alkaline. The overflow reservoir served as a natural disturbance reducing the phytoplankton biomass to less than 50 % and the dominance of cyanobacteria, promoting the domain of functional groups F, M, MP, Lo, and X2. The nutrient inputs from intensive fish farming, associated with a low local depth (Zmax = 7.7 m) close to the cages (PNC), resulted in a significant human disturbance that increased the prevalence of functional groups S1, SN, and K, which are composed primarily of cyanobacteria. We concluded that, in reservoirs, overflow events are natural disturbances that have the ability to reduce phytoplankton biomass and alter the structure of local communities, and that intensive fish farming is an anthropogenic disturbance that increases the availability of nutrients and stimulates an increase in biomass of the functional groups that include cyanobacteria. Furthermore, the functional groups of phytoplankton were reliable control of environmental conditions in the reservoirs of tropical semiarid regions. Rev. Biol. Trop. 65 (3): 1129-1141. Epub 2017 September 01.


Resumen: La estructura de grupos funcionales del fitoplancton y la abundancia de especies varían de acuerdo con las condiciones ambientales. Este estudio investigó los estresores naturales y antropogénicos que afectan la biomasa de grupos funcionales de fitoplancton en una represa (la represa de Argemiro de Figueiredo) en una región semiárida de Brasil. La recolecta de datos fue entre agosto 2007 y julio 2009 de forma bimensual durante el primer año, y de forma mensual durante los últimos dos años. Estos se recolectaron en tres sitios (PC: confluencia del río; PNC: cerca de las jaulas; PD: sitio de la represa). El análisis de las variables abióticas del agua incluyó: temperatura, transparencia, coeficiente de atenuación vertical de la luz, oxígeno disuelto, pH, conductividad eléctrica, alcalinidad, nitrógeno inorgánico disuelto y fósforo reactivo soluble. Las muestras de fitoplancton fueron recolectadas en una botella Van Dorn, y fueron preservadas en lugol acético y cuantificadas utilizando un microscopio invertido para determinar la densidad y la biomasa del fitoplancton, las especies identificadas fueron agrupadas en grupos funcionales. Los datos fueron explorados mediante un análisis de correspondencia canónica. Los análisis individuales fueron hechos para probar la variabilidad espacial y temporal de los datos y los factores que más interfieren con las variables bióticas y abióticas. Los grupos funcionales S1, SN, y K, incluyen las algas filamentosas: Planktothrix agardhii (Gomont) Anagnostidis & Komárek, Cylindrospermopsis raciborskii (Woloszynska) Seenaya & Subba Raju, y algas cocoides: Aphanocapsa incerta (Lemmermann) Cronberg & Komárek, respectivamente dominando los meses cálidos cuando el agua estuvo caliente, turbia y alcalina. El desbordamiento de la reserva funciona como una alteración natural, reduciendo la biomasa del fitoplancton a menos de un 50 % y la dominancia de cianobacterias, promoviendo el dominio de los grupos funcionales F, M, MP, Lo y X2. La llegada de nutrientes debido a la pesca intensiva, asociado con una baja profundidad local (Zmax = 7.7 m), cerca de las jaulas (PNC), resulta en una alteración humana significativa que incrementa la prevalencia de los grupos funcionales S1, SN y K, los cuales están compuestos principalmente por cianobacterias. Concluimos que, en las represas, eventos de desborde son perturbaciones naturales que tienen la habilidad para reducir la biomasa del fitoplancton y alterar la estructura de las comunidades locales, y que la pesca intensa es una alteración antropogénica que incrementa la disponibilidad de nutrientes y estimula el incremento de la biomasa de los grupos funcionales que incluyen las cianobacterias. Además, los grupos funcionales de fitoplancton fueron controles confiables de las condiciones ambientales en las represas de las regiones semiáridas tropicales.

13.
Food Chem ; 215: 454-62, 2017 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-27542498

RESUMO

Production of virgin olive oil is beginning in Brazil. This paper analyzes the characteristics of the EVOO Arbequina from Brazil in comparison with Spanish Arbequina from different regions. Quality parameters, oxidative stability, pigments, colour and fatty acid profile were assessed, and relationships with geographic and climatic conditions were studied. All the samples presented good quality and met EU standards for extra-virgin olive oil, but there were significant differences between regions and countries for many of the parameters evaluated. Major differences between Brazilian and Spanish samples were observed for free acidity and colour of the oils, as well as minor variations in the fatty acid profile. The colour differences were related to rainfall, whereas the fatty acid content was strongly influenced by altitude and temperature. These results highlight the fact that geographic area and environmental factors influence the characteristics of Arbequina oil and play an important role in newly introduced cultivars.


Assuntos
Azeite de Oliva/química , Óleos de Plantas/química , Brasil , Estresse Oxidativo , Espanha
14.
Acta sci., Biol. sci ; Acta sci., Biol. sci;37(3): 309-318, jul.-set. 2015. ilus, tab
Artigo em Inglês | LILACS | ID: biblio-847247

RESUMO

The Carlson's (1977) Trophic State Index (TSI) is a widely employed tool to estimate the degree of eutrophication in a reservoir. In Brazil, the need of a classification system that would take into account regional characteristics employed adjusted indexes generated by data from reservoirs in the southeastern region of the country. Current research compares responses for Carlson's TSI (1977) and its derivations for Brazilian reservoirs from data collected in the Pereira de Miranda Reservoir (State of Ceará, Brazil), and analyzes the influence of local conditions on results and their applicability to reservoirs in the semiarid region. TSIs were calculated by data on total phosphorus, chlorophyll a and water transparency. The reservoir was estimated as mesotrophic based on the chlorophyll a variable, and between eutrophic and hyper-eutrophic when based on total phosphorus data and water transparency. Results showed the need to consider intrinsic factors in the discussion on the applicability of TSIs to reservoirs in the semiarid region since the peculiar hydro-climatic conditions and morphometric characteristics make them even more vulnerable to disturbance agents, such as winds which have a significant influence on processes that determine the trophic state.


O índice de estado trófico (IET) de Carlson (1977) é uma ferramenta muito utilizada para estimar o grau de eutrofização de reservatórios. No Brasil, a necessidade de um sistema classificatório que levasse em consideração as peculiaridades regionais resultou em derivações do índice original. O objetivo desta pesquisa foi comparar as respostas do IET de Carlson (clima temperado) e dos índices modificados para reservatórios do sudeste brasileiro (clima subtropical) originadas para dados do açude Pereira de Miranda e analisar a influência das condições locais sobre esses resultados, discutindo-se a sua aplicabilidade para a região semiárida do Brasil. Os índices de estado trófico foram calculados a partir dos valores de clorofila a, fósforo total e transparência da água. O estado trófico do açude foi estimado como mesotrófico, com base na variável clorofila a, e entre eutrófico e hipereutrófico, com os dados de fósforo total e de transparência da água. A partir dos resultados, observa-se a necessidade de considerar fatores intrínsecos na discussão sobre a aplicabilidade desses índices para os reservatórios do semiárido, especialmente quando as variáveis hidroclimáticas e morfométricas os tornam ainda mais vulneráveis a distúrbios, a exemplo do vento, que tem influência significativa sobre os processos que determinam o estado trófico


Assuntos
Clorofila , Eutrofização , Nitrogênio , Fósforo , Reservatórios de Água , Zona Semiárida , Níveis Tróficos
15.
Acta Sci. Biol. Sci. ; 37(3): 309-318, jul.-set. 2015. ilus, graf, tab
Artigo em Inglês | VETINDEX | ID: vti-15476

RESUMO

The Carlsons (1977) Trophic State Index (TSI) is a widely employed tool to estimate the degree of eutrophication in a reservoir. In Brazil, the need of a classification system that would take into account regional characteristics employed adjusted indexes generated by data from reservoirs in the southeastern region of the country. Current research compares responses for Carlsons TSI (1977) and its derivations for Brazilian reservoirs from data collected in the Pereira de Miranda Reservoir (State of Ceará, Brazil), and analyzes the influence of local conditions on results and their applicability to reservoirs in the semiarid region. TSIs were calculated by data on total phosphorus, chlorophyll a and water transparency. The reservoir was estimated as mesotrophic based on the chlorophyll a variable, and between eutrophic and hyper-eutrophic when based on total phosphorus data and water transparency. Results showed the need to consider intrinsic factors in the discussion on the applicability of TSIs to reservoirs in the semiarid region since the peculiar hydro-climatic conditions and morphometric characteristics make them even more vulnerable to disturbance agents, such as winds which have a significant influence on processes that determine the trophic state.(AU)


O índice de estado trófico (IET) de Carlson (1977) é uma ferramenta muito utilizada para estimar o grau de eutrofização de reservatórios. No Brasil, a necessidade de um sistema classificatório que levasse em consideração as peculiaridades regionais resultou em derivações do índice original. O objetivo desta pesquisa foi comparar as respostas do IET de Carlson (clima temperado) e dos índices modificados para reservatórios do sudeste brasileiro (clima subtropical) originadas para dados do açude Pereira de Miranda e analisar a influência das condições locais sobre esses resultados, discutindo-se a sua aplicabilidade para a região semiárida do Brasil. Os índices de estado trófico foram calculados a partir dos valores de clorofila a, fósforo total e transparência da água. O estado trófico do açude foi estimado como mesotrófico, com base na variável clorofila a, e entre eutrófico e hipereutrófico, com os dados de fósforo total e de transparência da água. A partir dos resultados, observa-se a necessidade de considerar fatores intrínsecos na discussão sobre a aplicabilidade desses índices para os reservatórios do semiárido, especialmente quando as variáveis hidroclimáticas e morfométricas os tornam ainda mais vulneráveis a distúrbios, a exemplo do vento, que tem influência significativa sobre os processos que determinam o estado trófico.(AU)


Assuntos
Níveis Tróficos/análise , Eutrofização , Nutrientes/análise , Fósforo/administração & dosagem , Nitrogênio/administração & dosagem
16.
Rev. biol. trop ; Rev. biol. trop;62(3): 1053-1072, jul.-sep. 2014. ilus, mapas, tab
Artigo em Espanhol | LILACS | ID: lil-753674

RESUMO

The nesting requirements of the Yellow-headed Parrot (Amazona oratrix) are poorly understood, despite their broad historical distribution, high demand for pet trade and current endangered status. Information concerning their nesting requirements is required in order to design specific restoration and conservation actions. To assess this, we studied their nesting ecology in the Central Pacific, Michoacan, Mexico during a ten year period. The analyzed variables ranged from local scale nest site characteristics such as nesting tree species, dimensions, geographic positions, diet and nesting forest patches structure, to large scale features such as vegetation use and climatic variables associated to the nesting tree distributions by an ecological niche model using Maxent. We also evaluated the parrot tolerance to land management regimes, and compared the Pacific nest trees with 18 nest trees recorded in an intensively managed private ranch in Tamaulipas, Gulf of Mexico. Parrots nested in tall trees with canopy level cavities in 92 nest-trees recorded from 11 tree species. The 72.8% of nesting occurred in trees of Astronium graveolens, and Enterolobium cyclocarpum which qualified as keystone trees. The forests where the parrots nested, presented a maximum of 54 tree species, 50% of which were identified as food source; besides, these areas also had a high abundance of trees used as food supply. The lowest number of tree species and trees to forage occurred in an active cattle ranch, whereas the highest species richness was observed in areas with natural recovery. The nesting cavity entrance height from above ground of the Pacific nesting trees resulted higher than those found in the Gulf of Mexico. We hypothesize that the differences may be attributed to Parrot behavioral differences adapting to differential poaching pressure and cavity availability. Nesting trees were found in six vegetation types; however the parrots preferred conserved and riparian semi-deciduous forest for nesting, with fewer nests in deciduous forest, while nesting in transformed agricultural fields was avoided. The main climatic variables associated with the potential distribution of nests were: mean temperature of wettest quarter, mean diurnal temperature range, and precipitation of wettest month. Suitable climatic conditions for the potential presence of nesting trees were present in 61% of the region; however, most of the area consisted of tropical deciduous forests (55.8%), while semi-deciduous tropical forests covered only 17% of the region. These results indicated the importance to conserve semi-deciduous forests as breeding habitats for the Yellow-headed Parrot, and revealed the urgent need to implement conservation and restoration actions. These should include a total ban of land use change in tropical semi-deciduous forest areas, and for selective logging of all keystone tree species; besides, we recommend the establishment of wildlife sanctuaries in important nesting areas, and a series of tropical forest restoration programs in the Central Pacific coast. Rev. Biol. Trop. 62 (3): 1053-1072. Epub 2014 September 01.


Los requerimientos de anidación del loro cabeza-amarilla (Amazona oratrix) son poco conocidos a pesar de su amplia distribución histórica, la alta demanda como mascota y estar en peligro de extinción. Esta información es necesaria para diseñar acciones específicas de restauración y conservación. Durante diez años estudiamos la ecología de anidación del loro en Michoacán, México. Las variables estudiadas incluyeron en escala local las especies de árboles-nido, sus dimensiones y posición geográfica, dieta y estructura de parches de bosque; y a mayor escala el uso de la vegetación y las variables climáticas asociadas a la distribución de árboles-nido, obtenidas con un modelo de nicho ecológico utilizando Maxent. También evaluamos la tolerancia del loro al manejo de la tierra, y comparamos los árboles-nido encontrados, con 18 árboles-nido de Tamaulipas (Golfo de México), estudiados en los ochentas en un rancho privado intensamente manejado. Los loros anidaron en árboles altos en cavidades del dosel, registramos 92 árboles-nido en 11 especies de árboles, pero el 72.8% se presentó en Astronium graveolens y Enterolobium cyclocarpum que califican como árboles clave. Los bosques de anidación presentan 54 especies de árboles como máximo, y 50% sirven como alimento, también las zonas presentan alta abundancia de árboles dieta. La menor riqueza de árboles y de árboles dieta se presentó en un rancho ganadero, mientras que las áreas en regeneración natural presentaron mayor riqueza. La altura de la entrada de la cavidad en los árboles-nido del Pacífico fue mayor que en los del Golfo de México. Hipotetizamos que las diferencias se deben al comportamiento del loro, adaptado a la presión diferencial de saqueo de nidos y disponibilidad de cavidades. Los árboles-nido se encontraron en seis tipos de vegetación, pero el loro prefirió el bosque tropical subcaducifolio conservado, y ribereño, anidó menos en bosque tropical caducifolio y nunca en campos agrícolas transformados, difiriendo de lo esperado por la disponibilidad de hábitat. Las principales variables climáticas asociadas con la distribución potencial de nidos son: temperatura promedio del trimestre más lluvioso, oscilación diurna de la temperatura, y precipitación del mes más lluvioso. Las áreas de presencia potencial de árboles-nido representan el 61% de la región, sin embargo la mayor parte es bosque tropical caducifolio (55.8%), y el bosque tropical subcaducifolio sólo ocupa 17%. Los resultados indican la importancia del bosque tropical subcaducifolio conservado como hábitat de reproducción del loro cabeza-amarilla, y muestran la urgente necesidad de implementar acciones de conservación y restauración. Las acciones deben incluir la prohibición del cambio de uso del suelo del bosque tropical subcaducifolio, y de la tala selectiva de especies clave, la creación de santuarios de vida silvestre en las áreas de anidación y programas de restauración de los bosques tropicales de la costa del Pacífico central.


Assuntos
Animais , Ecossistema , Comportamento de Nidação/fisiologia , Papagaios/fisiologia , México , Papagaios/classificação
17.
Sci Total Environ ; 473-474: 317-25, 2014 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-24374593

RESUMO

We evaluated the effects of soil properties and climate on concentrations of parent and oxygenated polycyclic aromatic compounds (PAHs and OPAHs) and azaarenes (AZAs) in topsoil and subsoil at 20 sites along a 2100-km north (N)-south (S) transect in Argentina. The concentrations of Σ29PAHs, Σ15OPAHs and Σ4AZAs ranged 2.4-38 ng g(-1), 0.05-124 ng g(-1) and not detected to 0.97 ng g(-1), respectively. With decreasing anthropogenic influence from N to S, low molecular weight PAHs increasingly dominated. The octanol-water partitioning coefficients correlated significantly with the subsoil to topsoil concentration ratios of most compounds suggesting leaching as the main transport process. Organic C concentrations correlated significantly with those of many compounds typical for atmosphere-soil partitioning. Lighter OPAHs were mainly detected in the S suggesting biological sources and heavier OPAHs in the N suggesting a closer association with parent-PAHs. Decreasing alkyl-naphthalene/naphthalene and 9,10-anthraquinone (9,10-ANQ)/anthracene ratios from N to S indicated that 9,10-ANQ might have originated from low-temperature combustion.


Assuntos
Monitoramento Ambiental , Hidrocarbonetos Policíclicos Aromáticos/análise , Poluentes do Solo/análise , Argentina , Solo/química
18.
Arq. ciências saúde UNIPAR ; 11(3): 211-216, dez. 2007. tab, graf
Artigo em Português | LILACS | ID: lil-501992

RESUMO

O presente estudo teve como objetivo avaliar a incidência da dengue e sua relação com as condições climáticas do município de Toledo - PR. Para isso foi realizada uma pesquisa descritiva do tipo ecológico misto, retrospectivo, referente ao período de 2001 a 2005, utilizando-se as seguintes variáveis para o conhecimento do diagnóstico epidemiológico e entomológico: distribuição da doença; distribuição espacial (município); temporal (ano, mês e estações); condições metereológicas (índice pluviométrico, umidade relativa do ar e temperatura). Os dados foram coletados no Instituto Tecnológico - SIMEPAR, na Vigilância Epidemiológica e na Secretaria de Combate à Dengue de Toledo. Os resultados obtidos demonstram que a incidência da dengue foi maior em 2002, quando atingiu 1,43/10.000 hab. e a sazonalidade do vetor foi variável, indo de dezembro a junho. Os dados sobre as condições metereológicas foram comparados com os períodos de incidência, utilizando-se a correlação de Spearman. Os dados da precipitação referentes aos meses de maior notificação de casos demonstraram pequena relação entre si. Já os dados da temperatura refletem o verão mais quente, que ocorreu no Estado do Paraná, durante o ano de 2002, no qual a incidência da dengue foi elevada, com uma correlação de aproximadamente de 40%.


This study evaluates the incidence of dengue and its relation with the climatic conditions of the city of Toledo - PR. A mixed ecological-retrospective-descriptive research concerning 2001-2005 was carried out by using the following variables for the epidemiological and entomological diagnosis: distribution of the illness; spatial distribution (city); weather (year, month, and seasons), and meteorological conditions (pluviometric index, relative humidity, and temperature). The data were collected in Technological Institute- SIMEPAR, the Health Surveillance, and the Toledo Bureau to Combat the Dengue. The results demonstrate that the incidence of dengue was higher in 2002, when it reached 1.43/10.000 habitants, and the seasonality of the vector was changeable, going from December to June. The data on the meteorological conditions were compared with the periods of incidence by using the Spearman? correlation. The data on the precipitation referring to the months of highest notification of cases showed little relationship among them. The data concerning the temperature reflect the hottest summer, which occurred in the state of the Paraná, in 2002, where the incidence of dengue was high with a correlation of approximately 40%.


Assuntos
Aedes , Clima , Dengue , Fatores Abióticos , Mudança Climática
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA